Lathe or other turning machines



Nov. 15, 1949 A. TREVENA 2,487,994

LATHE OR OTHER TURNING MACHINES Filed Dec. 8, 1945 2 Sheets-Sheet 1 25 Ill 7i ATTORNEY- NOV. 15, 1949 TREVENA 2,487,994

LATHE OR OTHER TURNING MACHINES Filed Dec. 8, 1945 2 Sheets-Sheet 2 \NVEHTOR n ATTORNEY Patented Nov. 15, 1949 LATHE OR OTHER- TURNING MACHINES Arthur Trevena. Olton; Birmingham, England, assignor to J. Brockhouse & Company, Limited, West Bromwich, England, a British company Application December 8, 1945, Serial No. 633,591 In Great Britain August 3, 1944 Section 1, Public Law 690, August s, 1946 Patent expires August 3, 1964 Claims. (01. 82- -19) This invention relates to lathes and other turning machines, hereinafter referred to and included in the generic' expression machine tool, and the invention is particularly applicable to machine tools of the kind wherein the work is rotated about its own aXis and is operated upon in turn by a plurality of tools mounted upon a common tool carrier which serves to present them successively to the rotating work, the tools being themselves held against rotation around the axis of the work. Machine tools produce on the work a surface which is of circular cross section. It is often necessary to produce on awork-piece portions of circular cross section and another portion or other portions of non-circular cross section 'such' for instance as hexagonal, square or octag- A further object of the invention is to provide fanew or improved form of tool holder for producing on the work suriaces of non-circular cross section, and which is readily'adaptable to work of varying forms.

Other objects of the invention will be apparent from the following description and the drawings accompanying same.

Referring to the drawings:

Figure 1 is a perspective view of part of a workpiece such as can be produced by the means hereinafter described.

Figure 2 is a side elevation of one form of tool holder embodying the present invention, and

Figure 3 is a'part sectional view on the line 3-3 of Figure 2.

Figures 4 and 5 are transverse sections on the lines 4-4 and 5-5, respectively, of Figure 2, and

Figure 6 is a view corresponding to Figure 4,

but showing an alternative construction.

' The present invention is particularly applicable to lathes of the capstan type, and in the construction illustrated in Figures 2 to 5 as applied to such a machine, the body Ill of the tool holder is of approximately U shape, one limb thereof being provided" with a spigot I2 which can be secured in the icapstan head I3 and the other Y 2 limb I4 being provided with a bearing I5 which is concentric with the work-piece I6, this bearing carrying a sleevev I! which is formed or provided with a ring I8 having a number of inwardly pro- J'ecting hardened and rounded pins or abutments l9 adapted to co-operate with a cam 20, secured to the tool supporting element 2 I.

The sleeve II associated with the ring I9 is provided with a pin 22 projecting parallel to its axis but offset therefrom, and this pin is adapted to engage with a member 23 provided on the rotating head of the machine which carries the work-piece I6.

The ring I8 having the abutments I9 thereon is thus rotated at the same rate as the workpiece IG.

The tool supporting element 2| is mounted on the U shaped body Ill for sliding movement transversely to the axis of the work-piece I6 and sleeve IT. A shank 24 provided on the supporting element 2| slides ina guide member 25 carried by the body In. Conveniently the shank 24 has a portion of rectangular section engaging in a groove 26 in the guide member 25 and between such portion and the tool socket 21 is a neck 28 of reduced'width which is engaged by two plates 29 secured to the edges of the groove 26. The guide groove'26 extends at right angles to the axis of the work-piece I6 and sleeve I'I, so that the tool supporting element 2| is constrained to slide in a direction towardsand away from such axis, carrying with it a suitable tool 30 mounted in the socket 21.

The cam 20 carried by the tool supporting element extends laterally therefrom into the plane of the ring I8, and is of suitable shape for engagement by the rounded abutments I9 projecting internally oi the ring I8. The operative profile of the cam 2ll'may be of arcuate form, with a smaller radius than. the interior of the ring I8, so that as each abutment I9 slides over the cam profile the tool supporting element 2| is displaced inwardly towards the axis of rotation.

Drilled longitudinally of the shank 24 of the tool supporting element 2| is a blind hole 3! containing a plug 32, a compression spring 33 being'engaged between the latter and a second plug 34 screwed into the mouth of the hole. A grub screw 35 carried by the portion 25 of the tool holder body I0. extends through a longitudinal slot 36 in the holder shank 24 into a diametral hole 31 in the plug 32 so that the latter is fixed in'relation to the body I0 and the spring 33 operates to return the supporting element 2| chined to hexagonal or other polygonal section as shown.

If desired, the cam profile may be such that the corners between the various'faoes of the poly;

sive inward strokes of said tool supporting element relative to said work axis, and spring means for retracting said tool supportin element after each inward stroke thereof.

2. In-a machine tool of the kind specified, a tool holder comprising a body having a pair of connected parts spaced apart along the axis of rotation oi hclwor s, one f i y parts being gonal section are bevelled .or rouded ofl by the tool 30.

Alternatively, a succession of surfaces which l,

outwardly of said body parallel to but offset from are either concave or convex may-be'produced by the cam 20, or the latter may be designed for producing non-circular sections otherth'an poly gonal, as for instance, when it is desired to turn a portion of the work-piece elliptical section. a

Figure 6 illustrates a. modified construction in which, instead of a cam n the oo suppo t n element 2| being enga ed. y p ural y o abutments on the ring l 8 the latter is provided with a plu alit o cam es 35 f r c b ation with a s n le a utment 3970.11 the suppo in lement 2|. 7 a i This abutment 39, or the abutments IQ of the p ding ons ru tion, may be ep aced b small rollers, if desired,

In thefirst construction, the non-circular sec= t on pro d on t e W r -P c 6, d p n nt upon the number of abutments l9 and the profile of the cam 20, whilst in Figure 6 the determining factors are the number and form of the cam surfaces 38. a

To enable a single tool holder to be used for producing a variety of different sections, the sleeve I8 is made detachable from the body [0, and the cam 20 (or a block 40 carrying the single abutment 39) is made detachable from the tool supporting element 2!. 7

It will be understood that a tool holder constructed as above described operates equally well when the work-piece I6 is held stationary and the shank l2 of the body is engaged by the rotating head of the machine.

The body I 0 of-the tool holder need not'necessarily be of U shape as shown. For example, it may be cylindrical, in which case the part II may be represented by a complete annular web connecting one end of the cylinder to the'spigot l2, the'part 14 also being of annular form'and fitting into the other end of the cylinder.

What I claim then is: a

1. In a machine tool of the kind specified, a tool holder comprising a body having a pair of conected parts spaced apart along the axis of rotation of the work, one of said body parts being mounted detachably and non-rotatably on said tool carrier, the other of said body parts having an opening therein, a ring'mou'nted in said opening for rotation about the axis of the work, a driver operably associated with said ring and projecting outwardly of said body'parallel to but offset from the work axis, a tool supporting element disposed between said body parts and mounted slidably on said body for oscillatory movement towards and away from the axis of the work, said element being adapted detachably to carry a tool disposed between said body parts, a follower operably associated with said tool supporting element, and extending into the interior 'of the ring at one side of said work axis, said ring being provided internally with a plurality of angularly disposed abutments adapted successively to engage said follower to produce succesmounted detachably and non-rotatably on said tool carrier, the otherof said body parts having an opening therein,a ring mounted in said opening for rotation about the axis of the work, a driver operably associated with said ring and projecting the work axis, a tool supporting element disposed between said body parts and mounted slidably on said body for oscillatory movement towards and away from the axis of the work, a tool mounted 'detachably on said tool supporting element with its shank transverse to the work axis, a follower 'operably associated with said tool supporting element'and extending into the interior of the ring at one side of said work axis, said ring'being pro vided internally with a plurality of angularly spaced cam surfaces adaptedsuc'ces'sively to en-'- gage said follower to produce successive inward strokes of said tool supporting element relative to said work axis, and spring means for retract-v ing said tool supporting element after each in- Ward stroke thereof.

' 3. A tool holder for a machine tool for use in forming work of non-circular form and comprise ing in combination a body having a pair of spaced connected parts, one of said parts being adapted for detachable mounting on the tool carrier of the machine tool, the other of said body parts having an opening therein, a ring mounted rotatably in said opening, a driver operably associated with said ring, a tool supporting element disposed between said body parts and mounted slidably on said body for oscillatory movement towards and away from the axis of the work, said element being adapted detachably to Carry a tool disposed between said body parts, a. follower operably associated with said tool supporting element'and extending into the interior of the ring at one side thereof, said ring being provided internally with a plurality of angularly disposed abutments adapted successively to engage said follower to produce successive inward strokes of said tool supporting element relative to said work axis, and spring means for retracting said tool supporting element after each inward stroke thereof.

' 4. A tool holder for a machine tool for use in forming work of non-circular form and comprising in combination a body having a pair of spaced connected parts, one of said parts having a spigot adapted for detachable mountin on the tool carrier of the machine tool, the other of said body parts having an opening therein, a ring mounted rotatably in said opening, a driver operably associated with said ring, a tool supporting element disposed between said body parts and mounted slidably on said body for oscillatory movement towards and away from the axis of the work, said element being adapted detachably to carry a tool disposed between said body parts, a follower operably associated with said tool supporting element and extending into the interior of the ring at one side thereof, said ring being provided internally with a plurality of angularly disposed abutments adapted successively to engage said follower to produce successive inward strokes of said tool supporting element relative to said work axis and spring means for retracting said tool supporting element after each inward stroke thereof.

5. In a capstan lathe, a tool holder comprising a body having a pair of connected parts spaced apart along the axis of rotation of the work, one of said body parts being mounted detachably and non-rotatably on said tool carrier, the other of said body parts having an opening therein, a ring mounted in said opening for rotation about the axis of the work, a driver operably associated with said ring, and projecting outwardly of said body parallel to but offset from the work axis, a tool supporting element disposed between said body parts and mounted slidably on said body for oscillatory movement towards and away from the axis of the work, a tool mounted detachably on said tool supporting element with its shank transverse to the work axis, a follower operably associated with said tool supporting element and extending ARTHUR TREVENA.

REFERENCES CITED The following references are of record in the file of this patentf UNITED STATES PATENTS Number Name Date 473,027 Smith Apr. 19, 1892 

